little less so, but even that must be so 'figured' by the structural engineer if you ask him to 'figure' it. Now the Greeks developed this simple act of super-imposition pretty far by way of innate tasteful refinement. The Greeks were true aestheticians. Roman builders too, when they forgot the Greeks and brought the beam over as a curve by way of the arch, did something somewhat new but with consequences still of the same sort. But observe, all architectural features made by such 'Classic' agglomeration were killed for us by cold steel. And though millions of classic corpses yet encumber American ground unburied, they are ready now for burial. Of course this primitive post-and-beam construction will always be valid, but both support and supported may now by means of inserted and welded steel strands or especially woven filaments of steel and modern concrete casting be plaited and united as one physical body: ceilings and walls made one with floors and reinforcing each other by making them continue into one another. This Continuity is made possible by the ten- uity of steel. So the new order wherever steel or plastics enter construction says: weld these two things, post and beam (wall and ceiling) together by means of steel strands buried and stressed within the mass material itself, the steel strands electric-welded where steel meets steel within the mass. In other words the upright and horizontal may now be made to work together as one. A new world of form opens inevitably. Where the beam leaves off and the post begins is no longer important nor need it be seen at all because it no longer actually is. Steel in tension enables the support to slide into the supported, or the supported to grow into the support somewhat as a tree-branch glides out of its tree trunk. Therefrom arises the new series of interior physical reactions I am calling 'Continuity'. As natural consequence the new aesthetic or appearance we call Plasticity (and plasticity is peculiarly 'modern') is no longer a mere appearance. Plasticity actually becomes the normal countenance, the true aesthetic of genuine structural reality. These interwoven steel strands may so He in so many directions in any extended member that the extensions may all be economical of material and though much lighter, be safer con- struction than ever before. There as in the branch of the tree you may see the cantilever. The cantilever is the simplest one of the important phases of this third new structural resource now demanding new significance. It has yet had little attention in architecture. It can do remarkable things to liberate space. But plasticity was modest new countenance in our American architec- ture at least thirty-five years ago in my own work, but then denied such simple means as welding and the mesh. It had already eliminated all the separate identities of post and beam in architecture. Steel in tension enters now by way of mesh and welding to arrive at actual, total plasticity if and when desired by the architect. And to prove the philosophy of organic architecture, form and function are one, it now enters architecture as the aesthetic countenance of physical reality. 501